The 12-volt power outlets in modern autos are used to power accessories, such as laptops, GPS navigational systems, cellphones and DVD players. In older autos, the 12-volt outlet is only used for a cigarette lighter.
The 12-volt power outlet can be used with adapters, USB adapters and power inverters. Plug-in adapters may come with electronics such as portable DVD players and cellphones to allow the owner to charge and use these electronics. Cellphones, tablets and other items with a USB cord are easily charged using the 12-volt power outlet. Power inverters change the DC current from the auto to AC current, making it possible to power items with a standard household plug.